Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false, establishing it as a safe read operation. The description adds behavioral context by highlighting its random nature, indicating that results will vary on each call, which aligns with idempotentHint=false. It also suggests typical use cases. This adds value beyond the structured data without contradicting annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences long, front-loading the core purpose in the first sentence and adding use-case context in the second. Every word earns its place—no redundancy, fluff, or restatement of the name. It is concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple random-access tool with three optional boolean parameters and an output schema, the description is sufficient. It explains the core function and typical use cases. Parameter details are fully covered by the input schema, and the output schema handles return value descriptions. There are no hidden complexities or missing prerequisites that need to be disclosed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The tool description does not mention or elaborate on the parameters (include_entities, include_bible_parallels, include_urantia_parallels), leaving their semantics entirely to the schema. Since the schema already provides thorough descriptions, the tool description adds no additional parameter meaning, so a 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Get a random paragraph from the Urantia Book.' It uses a specific verb ('Get'), identifies the resource ('random paragraph from the Urantia Book'), and distinguishes it from sibling tools like paragraphs.get (which retrieves specific paragraphs) and paragraphs.context (which provides surrounding context). The random aspect is explicit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear usage context: 'Great for daily quotes, exploration, or discovering new passages.' It implies when to use this tool (for casual discovery) but does not explicitly mention alternatives or exclusions, such as 'use paragraphs.get for a specific paragraph.' Since it gives context but not explicit when-not-to-use guidance, it merits a 4.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.